1. Field of the Invention
The present invention relates to a restoration device for BIOS stall failures and a method and a computer program product for the same. More particularly, the present invention relates to a restoration device for restoring a BIOS when the BIOS cannot start with a reduced restoration time and a high restoration probability and a method and a computer program product for the same.
2. Description of the Related Art
A watchdog timer is used in ordinary computers for the purpose of monitoring a system halt such as a system stall.
A timer value is set in advance in a watchdog timer and the timer value is decremented as time passes.
However, the decrement of the timer value is suspended as a result of execution of a system program when the processing operation of a BIOS (basic input/output system) progresses without any problem.
On the other hand, the timer is not stopped when a stall failure arises to the system. Then, time out takes place and a reset signal is issued when the timer value gets to 0 or a prescribed number.
Normally, only a single watchdog timer is provided to monitor a BIOS stall and a reset signal is issued at time out.
Therefore, when a BIOS cannot be started and is desirably reset quickly, the timer value gets to 0 or a prescribed number after a while as in the case of occurrence of a stall failure during a processing operation of the BIOS and a standby status takes place until the BIOS is reset.
When the data region of the BIOS is destroyed and the BIOS cannot be started any longer, it cannot be restarted and the system can no longer be restored.
To cope with this problem, JP-A-2002-251300 describes a technique of using watchdog timers of three different types.
The timer values of the watchdog timers are differentiated in terms of progress and the timer reading takes less time to progress in the order of the first watchdog timer, the second watchdog timer and the third watchdog timer.
When the software stalls, a restoration process is attempted by a software program when the timer value of the first watchdog timer gets to 0 or a prescribed number and time out takes place.
If the software cannot be restored, a system reset signal is issued and a restoration process is attempted when time out of the second watchdog timer takes place.
If the software cannot be restored either, the system power supply is turned off when time out of the third watchdog timer takes place. Subsequently, the system power supply is turned on once again and a restoration process is attempted.
However, the above-described stall monitoring technique is accompanied by the following problems.
The first problem is that, since the system is being monitored from the viewpoint of seeing if the system has stalled in the course of a process or not, the system cannot be reset immediately if it cannot be started.
The second problem is that, since the system is restarted when trying to restore the system, the system cannot be restored if the BIOS data region is destroyed.
Therefore, it is the object of the present invention to provide a restoration device to be operated when a BIOS is in a stall failure that can quickly restore the BIOS if the BIOS is in a condition of being unable to start and a method and a computer program for the same.